Sewing-machine



W. T. B. ROBERTS. SEWING MACHINE.

APmlcAxoN FILED Nov. I7. 1916.

Patented sept. 27,1921.

MMVM /@mvf mzwv@ W. T. B. ROBERTS.

SEWING MACHINE.

APPLICATION FILED Nov. I1, 191e.

1,391,978, v PatentedSept. 27, 1921.

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' APPLICATION FILED NOV. I7, 1916.

Pmteds'epf. 27,1921.

4 SHEETS- ET 3.

w. T. B, ROBERTS.

SEWING MACHINE.

APPLICATION min Nov. TT, 1916.

1,391,978. Patenasept. 27,1921.

ylflllllllllllll 2f@ lnmembr l j MMS/@4 UNITED STATES`v PATENT OFFICE.

WILLIAM THOMAS BUCXINGHAM ROBERTS, OF LEICESTER, ENGLAND, ASSIGNQR', BY

MESNE ASSIGNMENTS, T0 UNITED SHOEv MACHINERY CORPORATION, or Perrin SON, NEW JERSEY, A. CORPORATION OF NEW JERSEY.

` SEWING-MACHINE.

specieation of Lettereratent.

Patented sept. 2v, 192,1.

Application med November 17, 1916,. serialy ne. 131,905'.

ture of boots and shoes, ofthe type in which a thread to be drawn thro-ughA the work is passed around a. hooked .or barbed needle by a looper, and is especially applicable to machines of the class known as welt and turn shoe sewing machines. Ilsually in machines of the class indicated, a curved needle is looped by an arm carrying at its end a passage in the form of a short tube, through which the thread passes, this.' arm being operated to lay the thread around and into the barb of the needle for each stitch. In case of a breakage 'of the thread, which is caused vgenerally by contact of the'needle or thread with lasting tacks, it is-almost invariably necessary for Athe operato-r to re-thread the looper by hand, because the loose end of the thread has been pulled out ofthe looper-passageby the take-up devices'. This re-threading obliges the operator to put down the work and causes considerable loss of time. The primary object ofthe. present invention is to provide a looper re-threading mechanism which will minimize the loss of time required in lhand labor. Accordingly one feature of the inventionv contemplates the provision in a sewing machine 'of the type indicated of automatic means for performing the looper re-threading operation, preferably by opening the thread passage of the looper at its side and passing the thread into such open passage, whichis thereafter closed and the looper operated in the usual manner. In the illustrated embodiment of the invention, the looper threading mechanism is locked in inoperative position during the sewing operation and the sewing mechanism is brought to a stop and locke in inoperative position while the looper threading mechanism is in operation.

- Other features of the invention `consist in certain details yof construction and combinations of parts, the. advantages of which will be obvious to those skilled in the art. The various features of the invention are illustra-ted in the accompanying draw-ings, in which-` 'Y Figurel is a view in frontv elevation of a e. welt and `turn wax thread sewing machine embodying the preferred form of the invention; Fig. 2 is a View in side elevation, partly 1n section, of the machine shown in Fig'. 1; Fig. 3 is a detail view in front elevation of the looper threading mechanism Fig. 4 is a view in side elevation of the partsshown invFig. 3;

Fig. ,5 is a diagrammatic view illustrating the mechanism for klocking the looper threading mechanism in inoperative lposition and sion.; Y

Fig. 6 is a detail view, partly in section, of the improved looper;

Fig. 7 is a horizontal sectionof the looper thread passage taken on the line 7 7 of Fig. 6; y y

Fig. 8 is a vertical sectional view of the improved thread tension; and

Fig. 9 isa vertical section of the thread tension taken-on line 9-9 of Fig. 8.

The welt and turn sewing machine illustrated in the drawings is substantially the same in its construction and operationof partsas the sewing machine shown in the patent to EpplerfNo. 1,108,560, dated August 25, 1914. This machine is provided with the usual curved hook needle 10, looper 12,y thread finger 14, work support 1G, awl 18, and vchannel guide 20, all of which, with the devices for releasing the tenrthe exception ot the looper, have substantially the same construction and mode ot operation as the parts shown and described in the Eppler patent.

j The machine illustrated in the Vdrawings is provided With an automatic looper threading mechanism, which mechanism embodies the present invention in its preferred form, and consists of devices for opening and closing the looper thread passage, a thread clamp for holding the free end of the thread, a threading arm for engaging the thread extending from the take-up roll to the thread clamp and placing the thread in the A the thread passage.

looper thread passage, and means for operating these members. l

The looper 12 (Figs. 1, 3, 4, 6 and 7) has the same general shape as the looper shown in the Eppler patent, and is adjustably mounted in a carrier 24 which is pivoted to the usual slide 26. The upper end of the carrier 24 is provided with a slidingly mounted pin 28 which receives a pin on the end of a rocking lever 30. The motion imparted to the looper by the lever 30 and slide 24 is the same as that imparted to the looper of the Eppler patent. The looper consists of a lixed section 32 and a movable section 34, the lower ends of which are shaped to form a thread passage which is opened when the section 34 is movedaway from the section 32. The thread passage is opened along planes which are preferably formed tangentially to the thread passage, andproject from the thread passage in a direction opposite to that in which the thread moves around the passage while it is being placed around the needle and into the barb of the needle. Vith this construction each section of the thread pas*y sage is provided with a short face36 and a long face 38, and the joints of the two sections are so arranged that they will not catch or break the thread as it moves around The section 34 is normally held in a position toclose the thread passage by means of a wedge 40 which is mounted within the shank of the looper. )When the wedge is withdrawn `from `the section 34, the section is moved into-position to open the thread passage 'by vmeans of a spring-pressed plunger 42 which is mounted in the section 32. To operate the wedge 40 for opening and closing-the thread passage, the upper end oi' the wedge is engaged by an operating rod 44 which is slidablv mounted at the side or the carrier` 24. The rod 44 is normally held in a position to hold the thread passage closed by means ofV a tension spring 46 which is connected between a pin 48 in the machine frame and` a pin 50 in the rod 44. To open the thread passage the rod 44 is lifted by means oa lever 52 (Figs. 1 and 2) which positively withdraws the wedge 40 from the movable section 34. The lever 52 is pivoted to the machine trame and has one arm which engages an oi'lset end 54 of the rod 44 and a f second arm which carries a cam roll 56.

The cam roll 56 is held in engagement with a tace cam 58 on the edge olf' a cam disk 60 by means of a tension spring 62 which is connected between the lever 52 and the machine frame. j.

wWhen the thread passage of the looper is open the thread may be placed in the passage by means of the threading arm 63 (Figs. 1, 2, 3 and 4) which has a hook 64 on its lower end for engaging the thread side of the cam plate 66. Between the thread arm 63 and clamping plate 7 0 a pair of rolls 72 are mounted on the screws 68 and move in a cam groove 74 formed in the plate 66. The clamping plate 70 is connectedbymeans ofa'link 76 with a cam lever 78 which is mounted on a pivot 8O secured inean auxiliary machine frame 82. A` cam roll 84 is mounted near the upper end oi' the cam lever 78 and works 'in a cam groove 86 formed on the face of the cam disk 60.y The cam disk 60 is fixed on a shaft 88 which is journaled in the auxiliary frame 82. The connection between the link 76 and lever 7 8lis adjustable to permit the threading linger to be properly timed in its operation. With the above construction the hook of the threading arm 63 carries the thread down 4between the machine frame and looper and directly behind the looper. They lower end ofth'e cam groove 74 has a comparatively sharp turn so that when the threading hook has passed the lower end of the looper the thread arm is moved outwardly to place the thread againstthe face 38 of the thread passage in thesection 32 ofthe looper. The thread is held in this position by the thread arm until the wedge 40v is moved down to close the looper thread passage.

While the lthread arm is drawing down the'thread to thread the looper, the free end of the thread is Vheld by thethread clamp 90 (Figs. 2, 3 and 4) which consists of a lever Vpivoted to a. bracket 92 projecting from the machine frame. The upper end of the lever'90`is connected-by means of a link 94 withv a double-arm lever 96, 98, which is `pi-voted to the machine frame. rlhearm 98 of the lever is provided with a cam roll 100 (Fig. 2) which works in a cam groove 102 formed in the-face of a gear wheel 104. The gear wheel 104 is fixed to thesha'ft 88 so that itwill rotate the cam disk 60. yDuring the sewing operation the lower end of the thread clamp is held inthe path of the thread and. has an opening 106 through which the thread passes` in going to theV sewing point. One 'side of the openingv 106 is closed by aleaf spring 108 (Fig. 3) so that the thread may be easily placed in the opening. When the thread is broken it will generally be pulled out of the thread passage of the, looper by the movement of the usual take-up 110, but will remain in` frame and clamps the free end of the thread in the opening 106 between the abutment and the clamping lever 90. Any excess movement of the lever 96, 98 will be taken up by the compression springf114 which is mounted on the link 94 between a collar 116 on the link and the lower end of the lever arm 96. f

The cams which actuate the looper threading mechanism are operated by a half-revolution clutch which will be hereinafter termed the cam clutch. In one half revolution of the cam clutch, the looper threading mechanism is operated, and Vupon the following half revolution the looper threading mechanismis retracted to its normal inoperative position. To drive the cams a worm wheel 118, which meshes with teeth on the gearwheel 104, is mounted upon the lower end of a clutch shaft 120 that is journaled in the auxiliary frame 82. A clutch pulley 122 is loosely mounted on the upper end of the shaft 120 and is continuouslydriven by a belt 124 which runs between the pulley 122- and a pulley 126 o'n a continuously driven reversing shaft 128. The reversing shaft 128 is the same as that shown in the patent to Topham No. 1,099,326, dated June 9, 1914, and is employed in stopping the machine and bringing the stitch forming devices to rest in a` predetermined position, all of which is fully described in said patent. vA clutch member 130 -is splined to the shaft 120 and is normally moved into position to be locked to the pulley 122 by means of springs 132. The clutch member v130 vis moved out of clutching position by aclutch lever 134 which is controlled by a latch 136 that is opera-ted by the kgear wheel 104. The lever 134 is pivoted to the frame 82, and

its upper yoke end engages an annularA groove 137 1n the member 130. The-latch 136 is pivoted to the lever 134 and has a downwardly projecting dog 138 which is adapted to engage pins 139 mounted in the face of the gear wheel 104. A tension spring 140 is connected between the machine frame and the end of the latch 136 which tends to draw the latch and dog down into engagement with the pins 139. The direction of rotation of the gear wheel 104 is such that the clutch lever 134 will disconnect the member 130 from the pulley 122 when a pin 139 engages the dog 138.

Whenever the thread-is broken the operay tor stops the machine and may then throw the looper threading mechanism into operation without removingr the shoe from the shoe feeding and supporting devices. The looper threading cam clutch is thrown into operation by means of a hand lever 142 (Figs. 1, 2 and 5) which is mounted'at the front of the machine frame Vin a position convenient for the operator. An arm 144 vin the machine frame.

projects inwardly from the pivot 146 of the lever 142 and a lug 148 is formed on the end of the arm 144 in position to engage the lower end .of a foot 150. The foot 150 is pivoted to a releasing bar 152 slidably mounted in the frame 82, and provided with a dog 154 which engages the lower face of the latch 136. e Through these connections the latch 136 4will be lifted from the pin 139 with which it is in engagement, whenever thehand lever 142 is moved inwardly (Fig. 5). When the latch 136 is lifted, the springs 132 will move the clutch member 130 into engagement with the pulley 122, and the cam disk will be rotated until the dogr 138 of the latch 136 is again engaged by a pin 139 to disconnect the member 130 from the pulley122. The hand lever 142`is acted upon by a spring-pressed plunger 160 and its outward position is determined by the engagement of an abutment 156 on the lever with a hook 158 mounted The inward movementV of `the hand lever, when connecting the cam clutch, is limited by the engagement of a lug 162 on the hand lever with an abutment 164 on the machine frame.

The looper threading mechanism is locked in an inoperative position during the sewing operation. To this end a detent 166 (Figs. 95 2 and 5) is formed on kthelever 168, which stops the reverse rotation of the main cam shaft 172 of the machine and which is actuated during the reverse rotation of the cam shaft as the machine vstops by means of the 100 lever 170, as` fully explained in Patent No.

1,099,326 above referred to. .During the` Y `sewing operation the stop lever 168 is held looper threading mechanism into operation.

l/Vhen the machine is stopped and the cam shaft 172 reversed, the detent 166 is moved frombehind the` lug 167 to the position 1110 shown in Figs. 2 and 5, so that the hand lever 142 may be operated to throw the looper' threading mechanism into operation. vWhen'the machine is stopped in positiony for the looper threading mechanism to be thrown into operation, the thread tension is released so that the thread may be freely drawn for the looper threading operation.-

The tension releasing mechanism is substantially the same as that disclosed in the patent to Eppler above referred to, and consists of an arm 173 projecting from the lever 168, a rod 174pivotally vconnected to the arm 173, a brake lever 176 carrying a brake shoe 178 and arranged to be acted upon by 125 a collar on the rod 174, a brake drum 180 on the shaft of the tension wheel, and'springs 182 Vacting on the brake lever 176.

When the looper threading mechanism is thrown into operation the operating camswill maire one-half a revolution and stop,

leaving the thread arm 63 and thread clamp 90 in the position shown in Fig. 4. After the looper has been threaded the machine may be throivn into operation and the operation of the sewing machine Will auto-v matically restore the iooper threading mech anism into inoperative position. To accomplish this a pin 184 on the arm 98 of the actuating lever of the thread clamp projects into a slot 186 on the'foot 150 of the releasing slide 152. Vhen the lever 96, 98 is operated to clamp the thread end, the foot 150 will be moved into a position above a lug` 188 formed on the side of a cam lever 190 which is movable about the pivot 146. The cam lever 190 carries a roll 192 which ivorirs in a cam groove in a cam on the shaft 172. is the machine is started up to form the first stitch the lever 190 is raised, carrying with it the slide 152 and lifting the latch 136 to connect the cam clutch. rEhe cam clutch will then make a half revolution and be again stopped by the engagement cf the latch 186 with a pin 139 on the gear 104. luring this motion of the clutch. the looper threading mechanism Will be Withdrawn 'to inoperative position and the dog 150 ivill be shifted back so as to rest above the abutment 148 on the arm 144.

lllhile the looper threading mechanism is in operation, tne sewing machine is locked in an inoperative position. To accomplish this a three-arm locking lever 194, Fig. 2, is pivoted on the frame 82 and has an arm 196 which is held in engagement with the lower end of the clutch lever 134 by a tension spring 198, which is connected between the lever 194 and the machine frame. When the clutch lever 184 is moved by the springs 132 in connecting the cam clutch, a paivl 200 on the lever 194- will be moved into engagement with the teeth 202 formed on the peripheral edge of a cam 204 on the shaft 172. This paivl 200 Will prevent rotation of the cam shaft 172, While the looper threading mechanism is in operation. When the cam clutch is disconnected, the paivl 200 will be withdrawn from the teeth 202 so that the sewing machine may be placed in operation. The locking lever 168 and reversing lever 170 are shown in Figs. 2 and 5 in the position which they assume when the machine has been stopped with the stitch-forming devices in the predetermined position. At this time it Will be noted that a.y pin206 at the pivot of the levers 168 and 170 is withdrawn from a face 208 on the locking lever 194. This will permit the lever 194 to be moved to bring the paivl 200 into contact with the teeth 202 when the cam clutch is thrown in. At the time the cam clutch is connected to restore the looper threading mechanism to inoperative position the reversing lever 170 has been moved down- Wardly in starting the sewing machine, and the pin 206 will come into engagement with the face 208 on the lever 194. Therefore, when the cam clutch is operated through the cam lever 190, the pin 206 Will'prevent the lever 194 from being rotated so that the pavvl 200 Will not engage the teeth 202. With this construction the pavvl 200 Will only be placed into `locking engagement with the cam 204 When the sewing machine is stopped and the looper threading mechanism is put into operation by the hand lever 142.

As the thread passes to the sewing point it runs overa thread tension Wheel 210 around a thread truck 212 on the machine frame, and a thread truck 214 on the take-up 110. in the sewing machine shown in the Eppler patent an auxiliary take-up is located between the thread trucks 212 and 214, but it Will be seen from the drawings that the thread arm 63 and thread clamp 90 operate `in the position ordinarily occupied by the auxiliary take-up, and that the auxiliary taire-up is omitted. To provide an auxiliary take-up movement for the thread the thread tension inthe illustrated embodiment of the invention is constructed to have the auxiliary take-up motion. The thread tension shown in Figs. 8 and 9 consists of a tension wheel 210 which is connected to a brake shaft 218 oy means of two tension springs 220 and 222. The wheel 210 is attached to the flange of a sleeve 224 vvhichl is loosely mounted upon the shaft 218.y A flange 226 is formed on the shaft 218 and carries a pin 228 Which projects through a slot 230 formed in the Wheel 210 and sleeve 224. One end of the spring 222 is secured to the pin 228 and the other end of the spring is'fixed in a collar 232 which is fixed on the shaft 218. One end of the spring 220 is fastened toa pin 234 mounted in the Wheel 210 and sleeve 224, and the other end of the spring 220 is fixed in a-collar 236 which is secured to the shaft 218. `With the above construction the operation of the thread tension is as follows: When the brake 178 is removed from the drum 180 on the shaft 218, the tension Wheel 210 will move freely with the shaft and the thread canbe drawn oil. When the brake is acting on the drum 180 a pull on the thread vvill tend to rotate the tension wheel relatively to the shaft, first against the action of the spring 220 until the pin 234 has been moved into contact with the end of the spring 220, then against the action of both springs 220 and 222 until the edge of the slot 230 in the tension Wheel comes into contact with the pin 228. At this time the tension Wheel Will move With the brake shaft to give olf thread. If slack thread is given by the stitch forming devices While the tension Wheel is held by the springs 220 and 222, the thread will be taken up by the action of the springs. With this construction the thread tension, in Vaddition to its usuall operation, has a take-up motion similar to that usually producedby known forms of auriliaryv take-up levers and associated spring buffers.

Although vthe above thread tension is of special advantage in a machine employing a looper re-threading mechanism,` obviously the improved thread tension may be embodied in almost any type of wax thread sewing machine.

This thread tension forms the subject matter of a divisional application filed June 24, 1919, Serial No. 306,475.

1t will be seen that excess thread lis used in threading the looper, and if the tension is locked when the take-up 110 moves up in the formation of the first stitch after threading the looper, the thread will probably be broken. For this reason, when vthe cam clutch is thrown into operation to Withdraw the looper threading mechanism to inoperative position, the thread tension is released during the formation of the first stitch. To accomplish this, a rod 238 at the back of the machine projects through an opening in the brake lever 176 and has a collar 240 fast thereon which is adapted to engage the lever and move it against the action of the springs 182. The rod 238 is connected with one arm of a bell crank lever 242, which is pivoted in the auxiliary frame 82. A cam roll 244 is mounted on the other arm of the bell crank lever 242, and is held in contact with the surface cam 58 on the cam disk 60 by means of a tension spring 246, which is connected between the lever 242 and the machine frame. `With this construction, when the cam 60 is making its half revolution to withdraw the looper threading mechanism to inoperative position, the tension will be released only during the formation of the first stitch.

The operation of the machine is as follows: A shoe is presented to the shoe supporting and Jfeeding devices, and the sewing operation is performed in the usual inanner. 1f the thread breaks, the operator will stop the machine, and push in the hand lever 142 to connect the cam clutch. When the cam clutch is thrown into operation, the wedge will be moved down to open up the looper passage, the thread clamp 90 will be moved back to clamp the free end of the thread against the abutment 112, and the thread arm will be moved down behind the looper to place the thread inthe looper passage. The wedge will then be moved up to close the looper passage, and the looper is in condition to continue the sewing operation. When the machine is stopped, the brake 178 is removed from the tension so that the thread is free to be drawn off in threadin the looper. As the cams complete their first half revolution in threading the looper, the pawly 200 will be withdrawn from the teeth 202 of the cam 304 and the operator may then start the sewing operation. VAt thecommencement of the sewing operation, the cam 'clutch will be thrown into operation by the lever 190, and the cams and v104 will be given a half revolution to draw up the thread arm and move the thread clamp out into the path of the thread. As the thread clamp is moved out, the thread will be under tension and will be forced against the spring 68 and into the passage 106 in the thread clamp. While the first stitch is being formed the thread arm 63 e will not be withdrawn from behind the looper and the' thread hook 64 will act in the same way as the usual thread finger 14 in forming the stitch. At the time the cams have completed their second half revolution the looper threading mechanism will be withdrawn into inoperative position and be ready to be thrown into operation to thread the looper, by the hand lever 142.

The preferred embodiment of the invention. having been thus described, `what is claimed as new is:

1. A sewing machine, having in combination, stitch forming devices including a hooked needle and a looper and means normally inoperative during the sewing operation for threading the looper.

2. Asewing machine, having in combination, stitch forming devices including a hooked needle and a looper having a thread passage and means acting automatically, when thrown into operation, to place a thread in said passage.

3. A sewing machine, having in combination, stitch forming devices including a hooked needle and a looper, a looper thread` ing mechanism normally inoperative during the sewing operation and act-ing when thrown into operation to thread the looper while the stitch forming devices are at rest.

4'. A sewing machine, having in combination, stitch forming devices including a hooked needle and a looper, a looper threading mechanism, means for throwing said mechanism into operation, and means for preventing ythe operation of said mechanism until the stitch forming devices have come to a stop in a Vpredetermined position.

5. A sewing machine, having in combination, stitch forming devices including a hooked needle and a looper, a looper threading mechanism, and means to lock the threading mechanism in inoperative position during the sewing operation.

6. A sewing machine, having in combination, stitch forming devices including a hooked needle and a looper, a looper threading mechanism, and means to revent the stitch forming devices from being thrown 7; A sewing machine, having in combination, stitch forming devices including a hooked needle and a looper, a thread tension, means for threading the looper, and means for releasing the tension on the thread during the looper threading operation.

8. A sewing machine, having in combination, stitch forming devices including a hooked needle and a looper, a thread tension, means for threading the looper, means for releasing the tension on the thread during the looper threading operation, and means for holding the tension released during the formation of the first stitch thereafter.

9. A sewing machine, having in combination, stitch forming devices including a looper having a thread passage formed of relatively movable sections, mechanism for placing a thread in the passage, and means to relatively move the sections of the looper thread passage to open the passage before the thread is placed therein, and t0 close the passage after the thread has been placed therein. p

l0. A sewing machine, having in combination, stitch forming devices including a looper having a thread passage therein, a looper threading mechanism comprising means for holding the free end of the thread, devices for opening and closing the thread passage and a thread arm Jfor placing thread in the passage.

1l. A sewing machine, having in combination, stitch forming devices including a looper having a thread passage formed of movable sections, and looper threading mechanism comprising means for holding the free end of the thread, devices-for opening and closing the thread passage, a thread arm for placing thread in the passage, and a series of cams for actuting the members of the looper threading mechanism, and means including a clutch for controlling the rotation of the cams.

l2. A sewing machine,having in combination, stitch forming devices including a looper, a looper threading mechanism, and means to operate the threading mechanism to thread the looper while the shoe remains in sewing position.

WILLIAM THOMAS BUCKINGHAM ROBERTS. 

